I have a pair of clowns, a small 3 stripe damsel and a dwarf midnight angel in my 30 gallon along with 4 hermit crabs. The water quality is perfect. Last week I added 2 turbo snails and a fire shrimp. Within a day the fire shrimp molted and within a week the snails died( I think they died because they were in the same place for a long time). Any ideas as to why this happened.?

In my opinion you should drip them much longer than that, more like an hour and a half or so. Inverts are much more sensitive to water changes than fish. Try acclimating them longer and see what happens